Python Manga Image Viewer

I'm currently making a manga (read: comic) viewer in Python. This project has been a code-as-you-learn project, because I have been trying to code this as I learned about Tkinter. Python I have known for some time, but not too long.

Performance-wise, I'm worried about the image loading and resizing time; it seems slow. I found out one thing by experimenting: when resizing "P" type images it is a lot slower than converting it to "L" (greyscale) and then resizing. Also the fullscreen is buggy, but this (and other minor bugs, coding format problems) is because I have thrown this together and haven't really re-coded it nicely yet (as I often do after I learn what I want it to be like, if you understand what I mean).

Format-wise, I don't think I have the best organization there is, maybe there is a better practice to hold up, or multiple files maybe (but Python can't do this?)?

Once again there are a lot of little bugs, like scrolling with the keyboard reveals extra space on the bottom, and the folder viewer doesn't always scroll to the selected folder in the dialog, and I would like to know how to fix this, but I would like more to know some good practices and optimization for image loading and resizing.

```
from Tkinter import *
from ttk import *
import Image, ImageTk, tkFileDialog, os

VERSION = "v0.0.3"

"""
folderDialog Class

Dialog that asks the user to select a folder. Returns folder and gets destroyed.

"""
class folderDialog(Toplevel):
def __init__(self, parent, callback, dir="./", fileFilter=None):
Toplevel.__init__(self, parent)
self.transient(parent)

self.title("Browse Folders")
self.parent = parent
self.dir = StringVar()
self.callback = callback
self.fileFilter = fileFilter

if os.path.exists(dir) and os.path.isdir(dir):
self.dir.set(os.path.abspath(dir))
else:
self.dir.set(os.path.abspath("./"))

self.body = Frame(self)
self.body.grid(r

As Moisei pointed out, Code Review isn't about functional issues. I guess performance can be discuted, but I don't know how to make resizing fast.

Your code looks good overall, but I don't know about Tkinter idioms. Here are a few comments:

-
You should check if __name__ == "__main__": before running the mainloop. This will allow you or someone else to import the code you written without having it launching the GUI.

-

st = ""
for title in titles:
    st = st + " " + str(title)

Write this as " ".join(titles)

-
#special super cool stuff here or even #newDir = os.path.join(newDir, "..")

Please care about comments.

StackExchange Code Review Q#4377, answer score: 5